1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // FIXME: (possibly) incomplete list of features that clang mangles that this
10 // file does not yet support:
11 //   - C++ modules TS
12 
13 #include "demangle/ItaniumDemangle.h"
14 #include "__cxxabi_config.h"
15 #include <cassert>
16 #include <cctype>
17 #include <cstdio>
18 #include <cstdlib>
19 #include <cstring>
20 #include <functional>
21 #include <numeric>
22 #include <utility>
23 
24 using namespace itanium_demangle;
25 
26 constexpr const char *itanium_demangle::FloatData<float>::spec;
27 constexpr const char *itanium_demangle::FloatData<double>::spec;
28 constexpr const char *itanium_demangle::FloatData<long double>::spec;
29 
30 // <discriminator> := _ <non-negative number>      # when number < 10
31 //                 := __ <non-negative number> _   # when number >= 10
32 //  extension      := decimal-digit+               # at the end of string
33 const char *itanium_demangle::parse_discriminator(const char *first,
34                                                   const char *last) {
35   // parse but ignore discriminator
36   if (first != last) {
37     if (*first == '_') {
38       const char *t1 = first + 1;
39       if (t1 != last) {
40         if (std::isdigit(*t1))
41           first = t1 + 1;
42         else if (*t1 == '_') {
43           for (++t1; t1 != last && std::isdigit(*t1); ++t1)
44             ;
45           if (t1 != last && *t1 == '_')
46             first = t1 + 1;
47         }
48       }
49     } else if (std::isdigit(*first)) {
50       const char *t1 = first + 1;
51       for (; t1 != last && std::isdigit(*t1); ++t1)
52         ;
53       if (t1 == last)
54         first = last;
55     }
56   }
57   return first;
58 }
59 
60 #ifndef NDEBUG
61 namespace {
62 struct DumpVisitor {
63   unsigned Depth = 0;
64   bool PendingNewline = false;
65 
66   template<typename NodeT> static constexpr bool wantsNewline(const NodeT *) {
67     return true;
68   }
69   static bool wantsNewline(NodeArray A) { return !A.empty(); }
70   static constexpr bool wantsNewline(...) { return false; }
71 
72   template<typename ...Ts> static bool anyWantNewline(Ts ...Vs) {
73     for (bool B : {wantsNewline(Vs)...})
74       if (B)
75         return true;
76     return false;
77   }
78 
79   void printStr(const char *S) { fprintf(stderr, "%s", S); }
80   void print(StringView SV) {
81     fprintf(stderr, "\"%.*s\"", (int)SV.size(), SV.begin());
82   }
83   void print(const Node *N) {
84     if (N)
85       N->visit(std::ref(*this));
86     else
87       printStr("<null>");
88   }
89   void print(NodeArray A) {
90     ++Depth;
91     printStr("{");
92     bool First = true;
93     for (const Node *N : A) {
94       if (First)
95         print(N);
96       else
97         printWithComma(N);
98       First = false;
99     }
100     printStr("}");
101     --Depth;
102   }
103 
104   // Overload used when T is exactly 'bool', not merely convertible to 'bool'.
105   void print(bool B) { printStr(B ? "true" : "false"); }
106 
107   template <class T>
108   typename std::enable_if<std::is_unsigned<T>::value>::type print(T N) {
109     fprintf(stderr, "%llu", (unsigned long long)N);
110   }
111 
112   template <class T>
113   typename std::enable_if<std::is_signed<T>::value>::type print(T N) {
114     fprintf(stderr, "%lld", (long long)N);
115   }
116 
117   void print(ReferenceKind RK) {
118     switch (RK) {
119     case ReferenceKind::LValue:
120       return printStr("ReferenceKind::LValue");
121     case ReferenceKind::RValue:
122       return printStr("ReferenceKind::RValue");
123     }
124   }
125   void print(FunctionRefQual RQ) {
126     switch (RQ) {
127     case FunctionRefQual::FrefQualNone:
128       return printStr("FunctionRefQual::FrefQualNone");
129     case FunctionRefQual::FrefQualLValue:
130       return printStr("FunctionRefQual::FrefQualLValue");
131     case FunctionRefQual::FrefQualRValue:
132       return printStr("FunctionRefQual::FrefQualRValue");
133     }
134   }
135   void print(Qualifiers Qs) {
136     if (!Qs) return printStr("QualNone");
137     struct QualName { Qualifiers Q; const char *Name; } Names[] = {
138       {QualConst, "QualConst"},
139       {QualVolatile, "QualVolatile"},
140       {QualRestrict, "QualRestrict"},
141     };
142     for (QualName Name : Names) {
143       if (Qs & Name.Q) {
144         printStr(Name.Name);
145         Qs = Qualifiers(Qs & ~Name.Q);
146         if (Qs) printStr(" | ");
147       }
148     }
149   }
150   void print(SpecialSubKind SSK) {
151     switch (SSK) {
152     case SpecialSubKind::allocator:
153       return printStr("SpecialSubKind::allocator");
154     case SpecialSubKind::basic_string:
155       return printStr("SpecialSubKind::basic_string");
156     case SpecialSubKind::string:
157       return printStr("SpecialSubKind::string");
158     case SpecialSubKind::istream:
159       return printStr("SpecialSubKind::istream");
160     case SpecialSubKind::ostream:
161       return printStr("SpecialSubKind::ostream");
162     case SpecialSubKind::iostream:
163       return printStr("SpecialSubKind::iostream");
164     }
165   }
166   void print(TemplateParamKind TPK) {
167     switch (TPK) {
168     case TemplateParamKind::Type:
169       return printStr("TemplateParamKind::Type");
170     case TemplateParamKind::NonType:
171       return printStr("TemplateParamKind::NonType");
172     case TemplateParamKind::Template:
173       return printStr("TemplateParamKind::Template");
174     }
175   }
176 
177   void newLine() {
178     printStr("\n");
179     for (unsigned I = 0; I != Depth; ++I)
180       printStr(" ");
181     PendingNewline = false;
182   }
183 
184   template<typename T> void printWithPendingNewline(T V) {
185     print(V);
186     if (wantsNewline(V))
187       PendingNewline = true;
188   }
189 
190   template<typename T> void printWithComma(T V) {
191     if (PendingNewline || wantsNewline(V)) {
192       printStr(",");
193       newLine();
194     } else {
195       printStr(", ");
196     }
197 
198     printWithPendingNewline(V);
199   }
200 
201   struct CtorArgPrinter {
202     DumpVisitor &Visitor;
203 
204     template<typename T, typename ...Rest> void operator()(T V, Rest ...Vs) {
205       if (Visitor.anyWantNewline(V, Vs...))
206         Visitor.newLine();
207       Visitor.printWithPendingNewline(V);
208       int PrintInOrder[] = { (Visitor.printWithComma(Vs), 0)..., 0 };
209       (void)PrintInOrder;
210     }
211   };
212 
213   template<typename NodeT> void operator()(const NodeT *Node) {
214     Depth += 2;
215     fprintf(stderr, "%s(", itanium_demangle::NodeKind<NodeT>::name());
216     Node->match(CtorArgPrinter{*this});
217     fprintf(stderr, ")");
218     Depth -= 2;
219   }
220 
221   void operator()(const ForwardTemplateReference *Node) {
222     Depth += 2;
223     fprintf(stderr, "ForwardTemplateReference(");
224     if (Node->Ref && !Node->Printing) {
225       Node->Printing = true;
226       CtorArgPrinter{*this}(Node->Ref);
227       Node->Printing = false;
228     } else {
229       CtorArgPrinter{*this}(Node->Index);
230     }
231     fprintf(stderr, ")");
232     Depth -= 2;
233   }
234 };
235 }
236 
237 void itanium_demangle::Node::dump() const {
238   DumpVisitor V;
239   visit(std::ref(V));
240   V.newLine();
241 }
242 #endif
243 
244 namespace {
245 class BumpPointerAllocator {
246   struct BlockMeta {
247     BlockMeta* Next;
248     size_t Current;
249   };
250 
251   static constexpr size_t AllocSize = 4096;
252   static constexpr size_t UsableAllocSize = AllocSize - sizeof(BlockMeta);
253 
254   alignas(long double) char InitialBuffer[AllocSize];
255   BlockMeta* BlockList = nullptr;
256 
257   void grow() {
258     char* NewMeta = static_cast<char *>(std::malloc(AllocSize));
259     if (NewMeta == nullptr)
260       std::terminate();
261     BlockList = new (NewMeta) BlockMeta{BlockList, 0};
262   }
263 
264   void* allocateMassive(size_t NBytes) {
265     NBytes += sizeof(BlockMeta);
266     BlockMeta* NewMeta = reinterpret_cast<BlockMeta*>(std::malloc(NBytes));
267     if (NewMeta == nullptr)
268       std::terminate();
269     BlockList->Next = new (NewMeta) BlockMeta{BlockList->Next, 0};
270     return static_cast<void*>(NewMeta + 1);
271   }
272 
273 public:
274   BumpPointerAllocator()
275       : BlockList(new (InitialBuffer) BlockMeta{nullptr, 0}) {}
276 
277   void* allocate(size_t N) {
278     N = (N + 15u) & ~15u;
279     if (N + BlockList->Current >= UsableAllocSize) {
280       if (N > UsableAllocSize)
281         return allocateMassive(N);
282       grow();
283     }
284     BlockList->Current += N;
285     return static_cast<void*>(reinterpret_cast<char*>(BlockList + 1) +
286                               BlockList->Current - N);
287   }
288 
289   void reset() {
290     while (BlockList) {
291       BlockMeta* Tmp = BlockList;
292       BlockList = BlockList->Next;
293       if (reinterpret_cast<char*>(Tmp) != InitialBuffer)
294         std::free(Tmp);
295     }
296     BlockList = new (InitialBuffer) BlockMeta{nullptr, 0};
297   }
298 
299   ~BumpPointerAllocator() { reset(); }
300 };
301 
302 class DefaultAllocator {
303   BumpPointerAllocator Alloc;
304 
305 public:
306   void reset() { Alloc.reset(); }
307 
308   template<typename T, typename ...Args> T *makeNode(Args &&...args) {
309     return new (Alloc.allocate(sizeof(T)))
310         T(std::forward<Args>(args)...);
311   }
312 
313   void *allocateNodeArray(size_t sz) {
314     return Alloc.allocate(sizeof(Node *) * sz);
315   }
316 };
317 }  // unnamed namespace
318 
319 //===----------------------------------------------------------------------===//
320 // Code beyond this point should not be synchronized with LLVM.
321 //===----------------------------------------------------------------------===//
322 
323 using Demangler = itanium_demangle::ManglingParser<DefaultAllocator>;
324 
325 namespace {
326 enum : int {
327   demangle_invalid_args = -3,
328   demangle_invalid_mangled_name = -2,
329   demangle_memory_alloc_failure = -1,
330   demangle_success = 0,
331 };
332 }
333 
334 namespace __cxxabiv1 {
335 extern "C" _LIBCXXABI_FUNC_VIS char *
336 __cxa_demangle(const char *MangledName, char *Buf, size_t *N, int *Status) {
337   if (MangledName == nullptr || (Buf != nullptr && N == nullptr)) {
338     if (Status)
339       *Status = demangle_invalid_args;
340     return nullptr;
341   }
342 
343   int InternalStatus = demangle_success;
344   Demangler Parser(MangledName, MangledName + std::strlen(MangledName));
345   OutputBuffer O;
346 
347   Node *AST = Parser.parse();
348 
349   if (AST == nullptr)
350     InternalStatus = demangle_invalid_mangled_name;
351   else if (!initializeOutputBuffer(Buf, N, O, 1024))
352     InternalStatus = demangle_memory_alloc_failure;
353   else {
354     assert(Parser.ForwardTemplateRefs.empty());
355     AST->print(O);
356     O += '\0';
357     if (N != nullptr)
358       *N = O.getCurrentPosition();
359     Buf = O.getBuffer();
360   }
361 
362   if (Status)
363     *Status = InternalStatus;
364   return InternalStatus == demangle_success ? Buf : nullptr;
365 }
366 }  // __cxxabiv1
367